Numbers in square brackets are used herein below as references to endnotes at the end of the description. Patent reference designators appear as standalone numbers or as numbers in parenthesis.
Chronic obstructive pulmonary disease (COPD) is a leading cause of morbidity/mortality in the United States and worldwide [1,2]. The leading cause of COPD is cigarette smoking, although newer data suggest that up to 25% of people with COPD have never smoked a cigarette in their lifetime. The disease typically takes two decades or more to become clinically apparent, producing a series of debilitating symptoms including chronic cough and shortness of breath. The disease is relentless with the development of one or more complications, such as progressive loss of lung function, lung infection, heart failure, or ruptured lung. Recent studies also emphasize a systemic component of the disease manifested as chronic weight loss, skeletal muscle weakness, and osteoporosis that may represent a chronic inflammatory component that contributes to morbidity and mortality [3].
Patients typically progress from having initial mild shortness of breath on exertion and performance of normal activities of daily living to severe shortness of breath in which the patient may require long-term oxygen therapy (LTOT) on a daily basis. The natural history of the disease is one of recurring exacerbations that bring the patient to medical attention with increasing frequency [1,2].
Prevalence/Morbidity/Mortality: Accurate morbidity, mortality and prevalence data suggest a huge and growing disease burden. In 2010, an estimated 24 million individuals in the US were identified with COPD. In addition, based on lung function tests, COPD was estimated to go undiagnosed in 50% of the COPD cohort (12 million). Since COPD is under-diagnosed, this is likely an underestimate of true prevalence. Individuals suffer progressive functional impairment and reduced quality of life as the disease progresses. COPD is the 3rd leading cause of death in the United States. Unlike cardiovascular disease, the prevalence and mortality of COPD worldwide is increasing due to continued exposure to risk factors [2].
Globally, there are an estimated 300 million people with COPD. It is a leading cause of death and disability worldwide. Current estimates indicate that it will be the 3rd leading cause of death worldwide by 2020. Unfortunately, the prevalence of COPD is growing related to the lack of progress with effective smoking cessation in many countries. The COPD burden will remain high for many years to come [4].
Economic/Societal Burden: The financial costs and burden to individual patients and society related to COPD is huge. Disease burden can be quantified in terms of direct costs (healthcare resources needed for direct care) and indirect costs (disability, missed work, premature mortality, and caregiver or family costs from the disease). It is estimated that lung disease costs the United States economy ˜$95 billion in direct health-care expenditures each year plus indirect costs of ˜$59 billion for an estimated grand total of $154 billion [1]. This cost to society is linked to the chronicity of this disorder. Indirect costs are important since they represent the human capital cost, an important national asset for the economic development of any society. Contrary to popular belief, COPD is not a disease of old people. In fact, it is estimated that approximately 70% of the COPD patients (24 million) in the US are less than 65 years of age, suggesting that many are still in the workforce [4].
In the United States in 2006, there were 16.3 million office outpatient visits, 1.5 million emergency department visits, and 673,000 hospital admissions for COPD [1,5]. Patients with COPD generate between $6,100 and $6,600 annually in excess health care costs, compared with patients without COPD and relative to other medical expenditures in the US. The per capita cost for hospitalization of patients with COPD was 2.7 times the cost for patients without COPD ($5409 vs. $2001). In 2010, total national medical costs secondary to COPD and its complications were ˜$32.1 billion with an additional 3.9 billion in absenteeism costs. The latter figure reflects the economic impact of this chronic disease that adds significantly to the overall economic costs of this chronic disease to society [6]. Recent estimates indicate that the cost of COPD to healthcare system in the United States is disproportionately spent on the patients with the most severe impairment.
The disability, suffering, and economic burden of this disease cannot be overemphasized [1,2]. Patients with COPD have a relatively high use of both outpatient and hospital resources. The total societal costs attributable to COPD are projected to increase significantly over the next decade (from $32.1 billion in 2010 to $49 billion) in 2020, suggesting that clinical interventions that result in more effective disease management are greatly needed and can significantly reduce the economic burden to society [6].